What structure in plant cells provides support and protection?

The cell wall is the structure in plant cells that provides both support and protection. It is primarily made of cellulose, which is a polysaccharide that gives rigidity and strength to the cell. This rigidity is crucial for maintaining the structure of the plant, allowing it to grow upright and withstand various environmental stresses.

Moreover, the cell wall serves as a protective barrier, shielding the cell from mechanical damage, pathogens, and fluctuations in osmotic pressure. Unlike animal cells, which only have a flexible cell membrane, plant cells benefit from the added stability and protection conferred by the cell wall, allowing them to maintain their shape and function effectively in their environment.

While the other structures listed serve important functions—like the cell membrane regulating what enters and exits the cell, the nucleus storing genetic material, and vacuoles maintaining cell turgor and storing substances—they do not provide the same level of structural support and protection as the cell wall does for plant cells.